1. Field of the Invention
The present invention relates to a three-dimensional model data generating apparatus for generating three-dimensional model data of a structural member constituting a machine tool in which a slide is movable in directions of at least first and second axes that are perpendicular to each other.
2. Description of the Prior Art
A machine tool is composed of various structural members such as: a chuck which holds a workpiece; a main spindle which axially rotates the chuck; a tool rest to which a tool is attached; and a drive mechanism which moves the tool rest in at least two orthogonal axial directions. Such a machine tool is configured so that the workpiece and the tool are relatively moved to machine the workpiece.
The operation of the drive mechanism is controlled by a controller on the basis of an NC program which is adequately prepared. If the NC program has an error, there is the possibility that an accident in which the tool and the workpiece interfere with each other occurs.
When an NC program is newly prepared, therefore, a trial machining is conducted on the basis of the NC program to check whether the NC program has an error or not. Recently, with using three-dimensional model data of a machine tool, an interference simulation is performed on a computer to check whether such an NC program has an error or not.
Such three-dimensional model data of a machine tool are configured while three-dimensional model data of plural structural members constituting the machine tool are correlated with one another. Three-dimensional model data of each structural member include at least shape data which define the three-dimensional shape of the structural member.
Usually, three-dimensional model data of a machine tool and structural members are adequately generated with using a three-dimensional CAD (Computer Aided Design) system by a CAD operator.
However, an interference simulation using three-dimensional model data which are generated in this way has the following problem. When the shape of a workpiece and that of a chuck for holding the workpiece are changed, for example, three-dimensional model data of the workpiece and the chuck must be newly generated, and three-dimensional model data of the whole of a machine tool must be corrected and updated with using the generated three-dimensional model data. As a result, there arises a problem in that the interference simulation cannot be quickly performed.
In a recent machining of workpiece, flexible production is conducted, and the workpiece shape to be machined is frequently changed. When three-dimensional model data of a workpiece and a chuck are newly generated for each change as described above, therefore, the productivity is very lowered.
Three-dimensional model data of a machine tool and structural members are sometimes caused to be different from their actual shapes by, for example, an error produced by a CAD operator. In this case, there is a problem in that an interference simulation cannot be correctly performed.
The invention has been conducted under the aforementioned circumstances. It is an object of the invention to provide an apparatus for generating three-dimensional model data which can generate efficiently and correctly three-dimensional model data of a machine tool and a structural member thereof in accordance with the actual state of the machine tool.